Field of the Invention
Various devices and compositions have been employed to condition fibers, fabrics, and laundry. Such conditioning may be effected with any of various suitable agents to improve a wide variety of properties of the materials treated. Generally, the most important conditioning effect is softening, especially with respect to cottons which have been laundered in aqueous solutions of heavy duty synthetic organic detergents. Also, and of increasing importance with the growing use of synthetic fabrics, the treatment of such fabrics and laundry material incorporating them has been desirable to diminish objectionable tendencies of such materials to become electrostatically charged, whereby they cling together or adhere closely and objectionably to various other surfaces. Of course, other conditioning may also be effected, such as making the treated articles antibacterial, soil-repellant, antifungal, perfumed, brightened, sized or lubricated. With respect to the various above treatments, especially with respect to softening fabrics and making them antistatic, the principal mechanisms employed in the past have relied on the substantivity of the treating material to the fabrics being treated. Thus, a treating chemical, dissolved in the last laundry rinse, becomes tightly held by the fabric and is not removed after discharge of the rinse water and subsequent drying. This, however, generally requires the presence of the launderer at the start of the last rinse to add the required material. Recently, such softening and/or antistatic agents have been applied to materials in conjunction with the drying operation. Thus, in U.S. Pat. No. 3,442,692, it is taught that various cationic conditioning agents can be used to impregnate flexible absorbent substrate materials, such as paper, cloth or sponge and can be vaporized from these as they are tumbled during a drying operation, so that they may be sorbed by the moving laundry present in the dryer. Paper-like substrates often adversely affect air flow by overlying vents or air holes. To this end, slits have been provided in the substrates as disclosed in U.S. Pat. No. 3,944,692. This may cause tearing of the substrate and adherence of smaller pieces thereof to the clothes being dried. Alternatively, the substrate has been mounted on a dryer door as disclosed in U.S. Pat. No. 4,053,992.
The use of absorbent material such as viscose is likely to cause a quantity of water to be absorbed not only increasing weight and product production time, but some loss of efficiency of the product.